Why is there white splotches on my render?
Your glossyness must be turned up a lot in your Principled shader for the skin. Try also messing around with the sub-surface shading, since it will give some more realistic results for the skin if tuned properly.

If you only gave one material for the entire head, try making some masks and give each part of the head (skin, hair, eyes) a different material, since in the real world they all have different surfaces.